SKS bolt trauma (reposted from gunsmithing)

[mljdeckard]

I bought a Yugo SKS from a friend of mine several years ago for $100. I tinkered with it, put Tapco stuff on it, kind of made it a learning project. (Mostly learning I'm not as handy as I think I am.)

I started having problems with it, I had a lot of failures to fire and one slam fire. That's when I decided to stop messing around, I called a smith, and he told me I likely had some cosmoline in the firing pin channel. I was skeptical, because I had cleaned the hell out of it and I thought that if that was the problem, it would have shown up a lot sooner. But I boiled it and soaked it in mineral spirits for a few days, and sure enough, some more cosmo oozed out. I scrubbed, blew, and rinsed it out and now I can't get any trace of anything.

Here's the problem now. The firing pin still won't exactly 'move freely'. The get it to move fully forward, I have to push it hard with my thumb, or give it a knock on a hard surface. I think there's still some kind of obstruction or damage in the channel or on the pin.

So I try to take it apart, and maybe I'm a wuss, but using punch and a BFH, I can't get the takedown pin to budge. I did some googling, and apparently the Yugos have that pin very tight to prevent halfwits like me from meddling with the bolt, where other SKSs are made so it comes out very easily. I laid it over a crack in my driveway and pounded it, I can't make it budge. I have a small vise, I put it in it, and when I whack it it falls right out. (The whole bolt assembly, not the pin.)

I also noticed that the tip of the firing pin appears to be mis-shapen, a little bit peened over. If I did this, I have no idea how.

So, I want to take the bolt apart, but I am afraid I will damage it. I'm not too worried about the shape of the pin as long as it works, but I wonder if some metal shaved off of somewhere, and it's still in the channel blocking motion.

I have the Tapco bolt they made for a while, with the trimmed rails to allow magazine removal and the sprung firing pin, but then I found out it needs to be head-spaced, it isn't drip-in. When I called Tapco about something else, they said they discontinued it because they were unable to work the bugs out of it. So I threw it in a drawer somewhere.

So I guess I'm wondering,

Do I need a new firing pin?

Do I have to take the bolt apart to figure out what's wrong?

Should I just find someone to headspace the Tapco bolt and forget about it?

 

[Comrade Mike]

Get a spring loaded firing pin from Murray's and never worry about it again.

 

[amx4080]

Sounds like you need to take the bolt apart to clean it, and possibly the firing pin has a burr.

Soak the area with some penetrating oil, and let it sit. Soak it the next day, and let it sit again.

Yes, the pin can be a bugger to pound out. Use a brass punch and hammer. It shouldn't take a huge amount of force to get the pin out. Once out, be careful of the extractor so you don't loose the spring.

To avoid further damage, use a block (or blocks) of wood. I drilled a big hole in a piece of scrap that allows the pin to move. The wood is hard enough to support the bolt but soft enough it won't do damage.

 

[dprice3844444]

http://www.milsurpstuff.com/proddetail.asp?prod=MSKSFP murray pin info
http://www.murraysguns.com/sksown.htm

http://www.kivaari.com/testimonials_post3.htm trigger work

 

[Steel Horse Rider]

Murry's is the way to go. I sent the bolts from both of my Yugo's there and am very happy with the results. The stock SKS firing pin is free floating so nothing holds it in the rear position, if the face is protruding when the bolt starts forward the base of the case or the primer is supposed to push it back into the bolt. When they are worn or dirty they don't always go back without a fight. The result can be a burst of full auto (I found out the hard way) that can be very surprising to the operator and bystanders. Maybe it is a good thing the Yugo with the grenade launcher is heavy as it makes it easier to control in that situation. Murray's installs a new firing pin with a spring that holds it in the proper position, like most modern firearms that are not manufactured by commies. I believe it is the best investment you can make for any SKS.

 

[Cee Zee]

The Murray firing pins only make the firing pin go backwards. If he has to push the pin forward to get it to go all the way then he will likely have light strikes and some failures to fire. You really need to get that firing pin out. Borrow another firing pin from a friend to see if it works. If it does then clearly it's a problem with the pin (which IMO is most likely because it's hard to get inside that channel to do damage but the tip of the firing pin can get buggered fairly easy if it gets hit hard when it's pushed forward out of the channel as far as it goes.

If the firing pin doesn't fix it try another bolt. I'm no gunsmith but I wouldn't think it would do great damage even though it wasn't headspaced. Use another Yugo bolt instead of the Tapco just to eliminate as many variables as possible. And I wouldn't put more than one round in the magazine at a time until I figure out what the problem is. The last thing you need is a firing pin stuck in the forward position because we're talking full auto until the mag empties.

 

[Redlg155]

See if you can borrow a headspace guage for 7.62x39. You would be surprised at the generosity of folks who will let you borrow one if you pay shipping to and from. If it doesn't headspace with the tapco bolt, then off to the smith as the work required is beyond normal user level. Especially if your "smithy" expertise involves a crack in the driveway and a BFH.

Option#2...as the others have said, penetrating oil and wood blocks. A good quality punch goes a long way as well.

Option#3- sell it at a profit with a disclaimer or send it to a smith.

To make you feel better, we all have had the BFH and dremel too days..

 

[barnbwt]

-Are you using the correct size punch, and perpendicular strikes, and a solid backer with good contact against the clamped bolt? If not, you likely aren't delivering nearly as much energy to the pin as you think you are, and will break your punch
-Is the pin deformed from the punch strikes? If yes, it is probably soft enough to be drilled out; a risky proposition, but doable with a press
-Did you try tapping the pin from the other side? The pin could be intentionally or unintentionally tapered, making removal from the insertion direction impossible
-Did you try penetrating oil, solvent, or heat? A couple hundred degrees should not harm anything, but would loosen up cosmo. Boiling water might not quite be enough.

You can headspace with brass, but only if you actually know what you are doing and how headspacing works. I would not advise it otherwise.

TCB

 

[mljdeckard]

Yeah, I used penetrating oil, heat, and honestly, I was hitting that sucker so hard I didn't care if I broke it. It didn't budge. The Yugo bolt has a flat head on the opposite side, there's no mistaking the direction.

I already did the Kivaari trigger, and yes, it's very good. I looked on Murray's web page, and I considered it. On one hand, it's a little pricey. On the other, I have already spent an absurd amount of time and money on this rifle, if I keep doing what I am doing, it will be covered with hammer and punch nicks, and THEN I will send it to him anyway.

But I am past my middle-school shop knowledge of ways to get this apart. Maybe I will take ot to my mom's house and use a bigger vise one more time. But yes, I have a good-size punch and a 5 lb hammer. If I can't get it out with that I'm probably over my head.

 

[Steel Horse Rider]

I think the Murray job was $45 including shipping when I did mine, a reliable SKS is certainly worth that without the brain damage of getting yours apart and then having to buy parts if the firing pin is bad. The Murray job includes a new firing pin, the spring, and stoning of the bolt face. I am puzzled as to how their price is too expensive.

 

[bainter1212]

I second the Murray's solution. Let the pros deal with your issue.
One thing to keep in mind MAKE SURE the Murrays mod is compatible with a Kivaari trigger job. Last I heard, the two could not exist together on the same gun (something about spring weight after the trigger job combined with the resistance of the Murrays pin spring).
A quick email to either craftsman should me informative.

 

[Kp321]

+1 on Murray's. Very good product and good people. I bought one of their pins from Brownells but could not get it into the bolt so called them. Found out they are two or three counties from here. Anyway, they said they had a batch of pins that warped in heat treatment but were inadvertently shipped. Told me to throw the pin away, they would send me a new one, no questions asked. Had it in two days.

 

[119er]

I have had a lot of these bolts apart and while they are pretty snug, you shouldn't have that much trouble. I am assuming that the FP is installed correctly and not binding on the cross pin. A nice, properly sized punch, a wood block with relief cut, and a small hammer should be all that is needed. Since you say all that is still not getting it, you may have a bad corrosion issue. Try tapping it back in from the opposite side. I know it has the rounded/squared head, but maybe it'll help it break free.

One particular Yugo gave me problems with the FP like you describe. The pin was actually peening the bolt face from the backside creating a sharp ridge that would then cut primers like a cookie cutter. Once fired, the "cookie" would be blown into the FP channel and bind up the pin. Three was the magic number it seemed. A Murray's pin and a few minutes with a file to remove the ridge eliminated my problem. Good luck driving that sucker out.

 

[MilsurpShooter]

I just did one of these this week on a Sino-Soviet. I spent 2 hours trying to break it loose before just walking away. PB Blaster, Kroil, Outers lubricating oil and WD-40 in varying degrees (PB Blaster I let soak overnight)

While it was still ungodly tight, after a 2 day soak I finally managed to get it out.

 

[Cee Zee]

Is the pin deformed from the punch strikes? If yes, it is probably soft enough to be drilled out; a risky proposition, but doable with a press
-Did you try tapping the pin from the other side? The pin could be intentionally or unintentionally tapered, making removal from the insertion direction impossible

Neither of these things are actually possible with the pin in question. It may be possible to drill it out but it would not be easy and you would need to replace it with another pin that came from an SKS. And the pin has a flat area on one side that isn't going through that hole.

BTW this same pin was a real bear on my Norinco. It's not just Yugos that have trouble with it. I eventually moved the pin just enough to get a very small screwdriver under it and I pried on it a good bit which helped get it moving. I'd pry on one side of the flat area then on the other side. Even now mine doesn't come apart all that easy and I've had it apart dozens of times checking that channel and the pin. All it takes is some powder buildup in that channel and you'll have a machine gun in your hands and people have gone to jail because of it (if you can believe what you read on these boards).

The real trick is getting something to hold back the bolt just right while you hit the pin with a punch. BTW if you think that part is bad wait until you try to clean the gas tube. It can be a nightmare to get the takedown lever to spin around. It took me several years to finally get mine to come apart. It has the scratches to commemorate those battles too.

 

[bainter1212]

Ok just got an email back from Tom Prince (aka Kivaari). He says the Murrays mod is OK, as he uses only the factory hammer spring weight on his trigger jobs.
You should be good to go sending your bolt to Murrays, let them deal with it.

 

[Cee Zee]

I've sent my bolt to Tom and I've bought the firing pin kit from Murray. I have nothing but good things to say about both of them. And if anyone can fix your firing pin issues it would be Murray IMO.

 

[mljdeckard]

I mailed it today, I will report back. I asked him for the carrier mod for the Russian-style firing pin, $60 total.

 

[mljdeckard]

Mr. Murray graciously called me and let me know that the previously mentioned 'peened over' firing pin I mentioned.....was not the firing pin. It was the remains of a blown-out primer that condomed itself in the channel over the firing pin. I looked on his website, and sure enough, this is a common problem with SKSs using the cheap Berdan-primed ammo we love so much. Not a problem, he can fix it.

 

[carbine85]

Have him do the upgrades while it's there. It will almost eliminate all slam fires.

 

[mljdeckard]

He is, that's why I sent it. He suggested the barrel reaming, I will hold off for now.